This winter I am going to rebuild the engine on my venerable R90/6. I have a reputable automotive machine shop that is going to rebuild the heads with new hardened valve seats on the exhaust and new valve guides. I have settled on the idea of buying the Seinbenrock big bore kit.
The engine in its present condition blows smoke on startup, is slightly down on power and has 150psi in the left cyl. and about 120 in the right. It doesn't make any funky noises and is generally still reliable. I would like to make sure that the engine stays together from here on out. I am going to inspect the cam chain and sprockets but unless they show obvious sign of age and wear I'm not going to change them. Question; who thinks I should go ahead and change them?
There is no reason to suspect that the crankshaft or connecting rods have any problem. Question; should I go into this motor that far, i.e., inspect the bearing surfaces, plasti-gage, etc?
I don't know the true mileage of this bike, I would guess at somewhere above 70k miles. Thoughts?
The engine in its present condition blows smoke on startup, is slightly down on power and has 150psi in the left cyl. and about 120 in the right. It doesn't make any funky noises and is generally still reliable. I would like to make sure that the engine stays together from here on out. I am going to inspect the cam chain and sprockets but unless they show obvious sign of age and wear I'm not going to change them. Question; who thinks I should go ahead and change them?
There is no reason to suspect that the crankshaft or connecting rods have any problem. Question; should I go into this motor that far, i.e., inspect the bearing surfaces, plasti-gage, etc?
I don't know the true mileage of this bike, I would guess at somewhere above 70k miles. Thoughts?